Social anxiety disorder characterized by fear of negative evaluation by others, high levels of anxiety and avoidance of social and functionally situations. The purpose of this study was to investigate Effectiveness of Task Concentration Training in reduction fear of others´ negative evaluation in people with social anxiety disorder. This study was a quasi-experimental study and the statistical population of this study consisted of all students of shahed university in the year of 1393-1394. These people investigated with social phobia questionnaire (connor and et. 2000), semi-structured interviews(Frest.1996) and Brief Fear of Negative Evaluation scale (Leary1983). Then 20 people with social anxiety disorder were selected and were replaced to experimental and control groups (each group n = 10) randomly. Task Concentration Training was used in the experimental group and control group waited. Results showed that the "Task Concentration Training" reduced the anxiety symptoms significantly compared with the control group(t=2/76, p=0/013). Therefore this results were consistent with other results and is primary underlying for using this technique in reduction fear of negative evaluation in iranian people with social anxiety disorder. Of course, we need further researches to showing benefit of this technique in different dimensions.